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Comments were received on this health consultation from a Lock Haven resident and from EPA
Region III. EPA comments were responses or explanations for a number of issues raised in this
consultation. Their comments are attached. If changes were made based on their comments,
ATSDR has added a response noting those changes. We also added responses to several of the
issues where further explanation of ATSDR's position was needed.

The resident submitted twenty-two newspaper articles and two reports from the Government
Accountability Project for our review and requested that we also consider the report issued by
Bob Martin, the EPA-Washington ombudsman. She also requested that ATSDR collect health
information from the local hospitals on cancers, lung problems, skin problems, and birth problems
including difficulties, defects, deaths, and miscarriages. She requested that this data be used as a
baseline for conducting a longitudinal health study of the Lock Haven area. The commenter also
questioned whether history would support that incineration is a safe technology or that it is a
dangerous practice that should be banned.

Occupational and community health studies have been conducted for the Lock Haven area for a
number of years to evaluate health outcomes related to the workers' and community's exposure
to b-naphthylamine (BNA) resulting from the Drake Chemical plant's operation and
production of BNA. Further health studies do not seem warranted at this time. Because of limited
resources and the expenses involved in conducting a longitudinal health study, ATSDR has
developed criteria for when it is appropriate to conduct a health study. One of the key criteria is
that there should be documented community exposure to contaminants at levels of public health
concern. In the draft Health Consultation #3, ATSDR evaluates the potential public health effects
from the incinerator. In that consultation, ATSDR concluded that the community is not likely to
experience adverse health outcomes due to exposure to contaminants from the Drake Chemical
Superfund site or emissions from the incinerator being used to remediate that site. If new
information is provided that indicates exposure of the public to contaminants at levels of health
concern, the Agency will re-evaluate the need for conducting additional health studies in the Lock
Haven community.

Incineration is a technology that has been around for hundreds of years. History so far has not
indicated that incineration is a dangerous practice that should be banned. There has been at least
one documented instance where a commercial hazardous waste incineration facility which had no
air pollution control equipment and operated under poor combustion practices did cause adverse
health effects in nearby residents (see Caldwell Systems, Inc. discussion in Appendix B).
However, stack testing and/or ambient air monitoring at many other incinerators have not
indicated releases at levels of health concern. In the last 15 - 20 years, hazardous waste
incineration practices and facilities in the USA have in general improved dramatically, so it is
unlikely that history will find that the newer facilities are so dangerous that they should be banned.
Appendix B contains a summary of the health studies related to incineration that ATSDR has funded.

The Preliminary Report Regarding Shakedown and Trial Burn Activities at the Drake Chemical
Superfund Site in Lock Haven, Pennsylvania, dated October 18, 1996, by the Government
Accountability Project raised the following issues. Each issue is addressed here, no changes were
made in the text of the health consultation.

Issue 1: When the mini-risk burn sampling for polychlorinated dibenzo-p-dioxin and
polychlorinated dibenzofuran (PCDD/F) and manganese was conducted soil had only been burned
for four hours before the sampling began. The authors were concerned that this was insufficient
time to establish a PCDD/F equilibrium due to the hysteresis effect that has been reported by
several researchers. Therefore, that data might be biased low.

ATSDR Response: We did not use the mini-risk burn data when evaluating the public's exposure
to PCDD/Fs and manganese in our Health Consultation #3. We used ambient air samples
collected at community monitors for two years and stack samples taken during the full risk burn
conducted in January 1997. The full risk burn was conducted after several months of burning
contaminated soil, so the hystereses effect should not be an issue with that data.

Issue 2: On October 9, 1996, the waste feed shut-off did not occur automatically within one hour
of the pH falling less than 6.0 like it should have. The issue was raised that the increase in HCl
could have caused an increase in PCDD/F formation.

ATSDR Response: It is our understanding that strict measures were put into place because of this
event to assure that operators assure compliance with the Pennsylvania specified operating
conditions and do not override automatic waste feed shut-offs (AWFSOs). To our knowledge no
such events have occurred since then. Health Consultation #2 endorsed the AWFSOs established
by the state of Pennsylvania, which includes the one-hour delay on low pH in the scrubber,
because there is an immediate AWFSO if the inlet temperature to the scrubber exceeds 250 oF.
Since this AWFSO will prevent the scrubber temperature from getting into the dioxin and furan
formation temperature range, an increase in hydrogen chloride (HCl) caused by a pH less than six
should not increase dioxin or furan emissions. A number of researchers have found that PCDD/F
formation does not increase with increased HCl concentrations; however it does correlate with
chlorine (Cl2) concentrations and the presence of copper and temperatures between 480 oF and
660 oF (1).

Issue 3: The issue was raised as to whether PCDD/F would increase during an event such as the
thermal relief valve opening on October 11, 1996, if contaminated soil was being processed at the
time. The point was made that the gases would be exiting at elevated temperatures and cooled in
the environment through the dioxin formation temperature range.

ATSDR Response: Fundamental laws of chemistry state that the precursor chemicals (products of
incomplete combustion) must come in contact with each other for a sufficient period of time to
react and form other chemicals such as dioxins or furans. This has been shown to occur in post
combustion equipment where gases remain for several seconds in the 480oF to 660oF dioxin and
furan formation temperature range. However, when the thermal relief valve opens and the hot
gases are vented to the atmosphere, the gases are not confined and the products of incomplete
combustion/reactants are not likely to be in close proximity to each other. Furthermore, they will
quickly cool to ambient temperature so it is highly unlikely that the necessary reactants will be in
contact with each other for several seconds in the ambient air in the necessary temperature range.
Therefore, it is highly unlikely that an increase in dioxin and furan formation would occur during a
thermal relief valve opening.

Issue 4: The authors pointed out mechanical problems that have occurred.

ATSDR Response: All mechanical devices (even brand new cars) have problems. The fact that
problems have occurred does not affect any of the conclusions or recommendations in Health
Consultation #3. The most important issue related to mechanical problems is did that event cause
public exposure to chemicals at levels of health concern? Health Consultation #3 evaluates the
data from the off-site community ambient air monitors and discusses the potential health impacts
based on that data.

Issue 5: Several regulatory issues were raised to EPA in this document.

ATSDR Response: ATSDR is not a regulatory agency and will only address health issues related
to the Drake site.

The Government Accountability Project Preliminary Report Number 2, Drake Chemical
Superfund Site, Lock Haven, Pennsylvania dated January 28, 1997, raised several additional
issues. Each issue is addressed here, no changes were made in the text of the health consultation.

Issue #1: The laboratory has analytical problems with the test method being used to measure
ambient concentrations of beta-naphthyl amine.

Issue #2: Was burned ash mixed with the contaminated soil that was burned during the trial burn
and risk burns in January 1997?

ATSDR Response: ATSDR inquired about the alleged occurrence of mixing burned ash with on-site contaminated soil. It is ATSDR's understanding that during the optimization period after
October 3, 1996, that the previously burned ash was placed on top of the contaminated soil
stockpile due to space constraints on-site. The previously treated ash is visibly different in color
and texture from the contaminated soil, so it is possible to see if previously treated ash is brought
into the feed building. The ash resulting from this testing is of a discernable color and texture that
can be differentiated from the contaminated on-site soil. Ash was said to be removed from the
stockpile, prior to the use of the contaminated soil for the trial burn tests. This occurred
approximately on January 2, 1997. Mr. Steve Jones, the TAG representative, has investigated this
occurrence. The trial burns did not occur until January 20, 1997. On that date, two U.S. Army
Corp of Engineer employees inspected the feed building to assure that no previously treated ash
was present. It is also ATSDR's understanding that Mr. Valentine, who originally brought up this
issue was no longer employed at the Drake site past November 30, 1996, so it is unclear how he
would have knowledge of what was burned during the January 1997 trial burns. ATSDR is unable
to prove or disprove soil mixing, but it appears that reasonable precautions were in place to
assure that only contaminated on-site soils were fed into the incinerator during the trial burns.

Issue #3: The bottom ash samples for both trial burn runs on 25 January 1997, should be
considered invalid because of alleged chain-of-custody violations.

ATSDR Response: Since the public is not exposed to the bottom ash, chain-of-custody of the
bottom ash samples is not a public health concern. This issue will not be addressed by ATSDR.

Issue #4: Beer drinking on-site is alleged to have occurred on 27 January 1997.

ATSDR Response: ATSDR agrees that beer drinking should not be allowed on the Drake site or
any other job site.

Issues #5 and #6 are comments regarding EPA procedural issues; not public health issues. They
will not be addressed here.

ATSDR has received and reviewed EPA Ombudsman Bob Martin's draft report and considered
his findings. Some of these issues have already been addressed in ATSDR's Health Consultations
#1 and #2, including review of the trial burn risk assessment, detection problems with BNA,
weather data availability, and site operations. Other issues have been discussed with EPA and will
be addressed in the third health consultation, after the data have been reviewed.

Twenty-two newspaper articles were reviewed to determine if they raised any additional issues
that are relevant to Health Consultation #2. None were specifically related to this consultation,
however quite a few articles raised issues related to the potential for public health effects due to
incinerator emissions. This issue is addressed in Health Consultation #3. Several articles also
raised the issue of soil blowing off-site. This issue is also addressed in Health Consultation #3. A
couple of articles discussed an odor problem that existed in 1995. Apparently that problem has
abated since there are no recent articles regarding this issue and we have not noticed a strong
odor problem during any of our site visits over the last couple of years. One article referenced an
ATSDR health study that found increased neurological and respiratory symptoms among residents
who lived near or downwind of an unnamed hazardous waste incinerator. The author suggested
that this is what the residents of Lock Haven could expect to happen to them. That health study
was a symptom and disease prevalence study conducted in the community around the Caldwell
Systems incinerator in North Carolina. That incinerator had been in operation for a number of
years without any air pollution control equipment. It was a very poorly run facility, that burned
some very toxic Navy wastes under conditions that were indicative of incomplete combustion.
The results of that study are not relevant to a state-of-the-art incinerator like the Drake Chemical
incinerator treating soil contaminated with parts per million concentrations of chemicals rather
than pure products. Other issues raised in these articles which are not within ATSDR's
jurisdiction to address are EPA regulatory and legal issues related to the AIR lawsuit, whether the
EPA record of decision should be reopened, and contracting costs.

EPA Response: The air quality modeling for acute effects will utilize the maximum hourly
estimated emissions for the normal operations of the incinerator. The modeling will utilize the
maximum estimated emissions to determine the annual average ambient concentrations for each
pollutant expected to be emitted from the incinerator. As the incinerator is not expected to
operate in a fashion that would generate the maximum emissions, the maximum values provide the
most conservative approach for the modeling and would overestimate the predicted ambient
concentrations and resultant deposition rates.

Comment 2:A comparison of the Williamsport wind data and the actual site-specific wind data
for the months that the data are available will provide additional scientific support to the use of
the Williamsport meteorological data. A time histogram or auto-correlation may be useful for
comparing the two data sets.

EPA Response: A comparison of the Williamsport, PA and onsite meteorological data is
presented in Section 4.1 of Volume III of the Drake Chemical Site Incinerator Trial Burn Risk
Assessment. A series of monthly wind roses for each data set has been developed to allow for a
side-by-side comparison of the wind patterns between Lock Haven and Williamsport, PA.

ATSDR Response: The wind roses do not adequately address our comments; therefore, no
changes were made.

Comment 3:The use of 5 years of meteorological data will help assure that likely worst case
public exposure concentrations are part of the evaluation.

EPA Response: One (1) year of a combined onsite and Williamsport, PA meteorological data is
used in the air quality modeling analysis for the full operation risk assessment. This approach
maximizes the influence of local conditions on the meteorological modeling. The use of the
combined database maximizes the available and quality assured onsite data for the air quality
modeling. However, four and one-half (4.5) years of Williamsport data were also evaluated to
ensure that temporal changes in the meteorological data were considered in the risk assessment.
This combined data set, including the six months of local Lock Haven data with the four and on-half years of Williamsport data, will be evaluated in a sensitivity analysis in Section 8 of the
current risk assessment for full operations.

Comment 4:Are there other sources of local meteorological data, such as the Piper Memorial
Airport, the state college, other industrial air sources, river and stream flow stations, etc.? A
definitive statement as to the unavailability or unsuitability of any such data (and what attempts
were made to locate other local data sources) would strengthen the full operation risk
assessment.

EPA Response: WESTON has investigated other possible sources of meteorological data in the
Lock Haven, PA data and there are no known sources of data meeting the siting or data
requirements for air quality modeling. A statement on the unavailability of local meteorological
data will be added to the full operation risk assessment.

Comment 5:The actual number of receptors used in the modeling for the trial burn is unclear. If
more than one model is used in the operational risk assessment, ensure that the same receptors
are used in each of the models.

EPA Response: A total of 8,571 receptors were utilized in the air quality modeling analysis. A
figure displaying the location of these receptors is Figure 2.5-1 of Volume III of the June 1996
risk assessment. The same receptor grid was used with the ISC3 and CALPUFF models.

ATSDR Response: In the Emissions Modeling , this comment (the fifth bullet) was deleted. EPA
has clarified that the same receptor grid was used in all the models.

Comment 6:The rationale for the use of CALPUFF, ISC3, INPUFF, and VALLEY is not clearly
explained. If all four models are used in the modeling protocol for full operation, it would be
helpful to include a clearer discussion of the rationale for the use of each model.

EPA Response: The rationale for use of each of the air quality models is described in Section 2.1,
General Methodology, of Volume III in the June 1996 Trial Burn Risk Assessment. The air
quality modeling analysis consisted of a primary and supplemental analysis for both the normal
trial burn emissions and upset conditions. The primary analysis for normal trial burn emissions
used the ISC3 air quality dispersion model, and the primary analysis for the upset condition used
the INPUFF model. The supplemental analysis for both normal emissions and upset conditions
used the state of the science model CALMET/CALPUFF. The VALLEY model was not used in
the analyses.

The ISC3 model was used to provide the primary estimate of all air concentration and deposition
fluxes required for the exposure assessment. The CALMET/CALPUFF model was used to
provide the concentration and deposition estimates using a more-comprehensive representation of
the local wind field and to provide a complete set of concentration and deposition estimates under
inversion/stagnation conditions. CALPUFF was used to provide a complete set of concentration
and deposition values. As with the ISC3 estimates, these values were used to produce a second
complete and independent set of risk estimates. The INPUFF model was used to estimate the
ambient concentrations due to a relief valve release, since it could appropriately represent the
varying emission rates and exit velocity of the relief valve release.

ATSDR Response: In the Emissions Modeling section, this comment (the sixth bullet) was
deleted. When ATSDR staff read Section 2.1 of Volume II of the June 1996 Trial Burn Risk
Assessment, they agreed that it provided a clear discussion of the rationale for the use of each
model.

Comment 7:The sensitivity discussion in Volume I of the trial burn risk assessment, Section 8,
compares ISC3 results with CALPUFF results, presumably at the same maximum concentration
locations derived from ISC3 results. CALPUFF might yield significantly higher concentrations
elsewhere. It is not clear whether each model was run independently to allow each one to project
maximum impact locations. If one forces the non-steady-state models to predict concentrations
at the same location as the ISC3 maximum location(s), the true maximum concentrations may be
underestimated for both normal and upset conditions.

EPA Response: The ISC3 and CALPUFF models were run separately using the same receptor
grid network. Maximum concentrations locations were determined independently for both models
and compared independent of location.

ATSDR Response: In the Emissions Monitoring section, this comment (the seventh bullet) was
deleted since EPA has clarified that both models were run independently.

COMMENT 8:The uncertainty and sensitivity analyses do not present quantitative assessment
of the air quality modeling results. One approach to quantifying the uncertainty and sensitivity
issues would be to exercise one of the models at a few locations, systematically varying the
various input assumptions. This would yield an ensemble of model predictions that could help
health scientists assess the values used in the risk assessment.

EPA Response: The Uncertainty Assessment does provide for a comparison of the two models
used for the air quality analysis. The differences and variability in the two models was considered
insignificant. The levels of conservatism embedded in the modeled assumptions was considered to
overestimate risks (e.g. use of maximum emission rates and consideration of the duration of
operation). Since the ISC3 and CALPUFF models were both run independently, and the
differences in the respective results were determined to be insignificant, other changes in variables
for subsequent model comparisons were deemed unnecessary.

ATSDR Response: Although we agree with EPA that comparing the two models was perhaps a
way to evaluate the relative uncertainty of the models, we still think a more quantitative sensitivity
analysis would be more convincing. When reviewing the comparison of ISC3 and
CALMET/CALPUFF modeling results in Volume III, Section 5.2 of the 21 June 1996, risk
assessment it is easy to agree that a 8% to 20% difference is not likely to affect the final risk
numbers. However, when you see 40% to 132% differences, it is not easy to say these differences
plus a factor of four difference for downwash and calm winds (Section 5.3) are insignificant when
considered in an aggregate form.

Comment 9:Volume III of the risk assessment assumes that the particulate released during a
TRV event would be primarily metals (not organics) and that they would be relatively large and
thus would deposit on site. This assumption is contrary to the information in Table 2.4-2 of
Volume I of the risk assessment. That table says all the metals except barium, beryllium, and
chromium will be 100% volatilized during normal and upset conditions. Barium will be 50%
volatilized, and beryllium and chromium will be 5% volatilized. It seems reasonable to assume
that most of the metals will be in the vapor state when exiting the TRV and will be dispersed in
the plume rather than being large particles that fall on site.

EPA Response: The air quality modeling for the TRV release utilized the emissions developed for
the process upset conditions. These emission calculations are in Volume II, Section 3B.3.3 which
presents the metal emission considering volatilization partition factors without emission controls.
The emission used in the INPUFF modeling were simulated as vapor emissions since no
particulate deposition was accounted for.

ATSDR Response: We have added references to our original comment to clarify which sections
we think are in conflict. Since Volume III of the risk assessment still appears to be in conflict with
other sections of the risk assessment, the comment has not been deleted. However, we do
acknowledge that it appears from Volumes I and II that EPA did use more reasonable metal
volatilization factors; contrary to the section in Volume III which discusses the uncertainties
associated with the INPUFF model that they used for TRV release modeling. If EPA did modify
the INPUFF model to assume the metals were vapor, then why doesn't Volume III, Section 5.3,
state that instead of saying the INPUFF model assumed all the particulate dropped on site?

Comment 10:EPA assumed that during TRV events, the particulate emissions would be 10,000
times those occurring during normal operations. If this is equivalent to zero removal efficiency,
the document should indicate that you are assuming no removal of particulate.

ATSDR Response: This comment was deleted (the tenth bullet). EPA is correct, their assumption
is clearly explained in Volume II, Section 3B.3.

Comment 11:ATSDR should review the draft proposal on how the full operation risk assessment
will project TRV emissions. The proposal should provide references to support any assumptions.

EPA Response: The plan for the consideration TRV emissions in the full operation risk
assessment is presented in the Work Plan for the full operation risk assessment, and is based upon
the same approach used in the June 1996 analysis.

ATSDR Response: ATSDR was not provided with the draft proposal on how the TRV emissions
would be projected or the "Work Plan for the full operation risk assessment". This comment was
reworded to clarify that we are requesting references for (1) the assumption that after an initial
puff of one minute duration, the emissions will decrease exponentially to zero within 25 minutes
and (2) the assumption that during the first minute the DRE will decrease from 99.99% to 99%.

CONCLUSIONS:

Conclusion 1:Automatic waste feed shut-offs (AWFSOs) were set on the key operating
conditions, and the documents specified that the flame was to be maintained whenever it was
safe to do so. The operating conditions and AWFSOs should ensure safe operation of the
incinerator and prevent or minimize to the maximum extent possible exposure of the community.

EPA Response: No response required.

Conclusion 2:The continuous monitoring and recording of the key operating conditions and
stack emissions will provide continuous documentation of the operation of the incinerator and
the causes of any releases that may occur.

EPA Response: No response required.

Conclusion 3:The circumstances specified when the thermal relief valve (TRV) would be opened
were only those that truly constituted emergency situations, when it would be more protective of
public health to vent the hot gases through the TRV than to allow catastrophic equipment failure
that would release the hot gases at ground level.

EPA Response: No response required.

Conclusion 4:Estimates of TRV emissions for full operation and modeling of those values
would help investigators predict the public health impacts of upset conditions.

EPA Response: The full operation risk assessment currently being drafted will include an
evaluation of upset conditions from TRV emissions. This evaluation will include the experience
gained in the trial burn as well as existing data from other similar sources and will involve both an
estimate of emissions and short term ambient dispersion modeling to appropriately estimate any
potential public health impacts.

Conclusion 5: New modeling would be useful for evaluating the stack emissions measured
during the trial burn. Modeling to date is not adequate to project the ground level
concentrations in the communities around the Drake incinerator during full operation.

EPA Response: New modeling of full operation emissions is currently being conducted as part of
the full burn risk assessment.

RECOMMENDATIONS:

Recommendation 1:Conduct new modeling using 5 years of meteorological data and stack
emissions rates measured during the trial burn and risk burn. Agency for Toxic Substances and
Disease Registry (ATSDR) staff should review the draft modeling protocol before the modeling is
conducted so that our input can be more pertinent and timely.

EPA Response: Modeling for the full operation risk assessment is underway pursuant to the work
plan for this project. As discussed above, one (1) year of meteorological data (six-months of Lock
Haven and six months of Williamsport) are used as the basis of the modeling for the body of the
risk assessment. This approach maximizes the influence of local conditions in the meteorological
modeling. A separate sensitivity analysis will be conducted to evaluate six months of on-site data
combined with four and one-half years of Williamsport data. The resulting modeled ambient
concentrations and depositions will be compared.

Measured stack emissions are being used as the basis for the calculation of emission rates during
the full operation.

ATSDR Response: No changes have been made in this recommendation. The draft modeling
protocol was not provided to ATSDR staff.

Recommendation 2:Reevaluate the assumptions used in projecting the emissions that will be
released when operating conditions cause the thermal relief valve (TRV) to open. ATSDR should
review and provide comments on the draft proposal on how TRV emissions will be projected in
the full operation risk assessment.

EPA Response: The emissions from the potential TRV openings are being reevaluated as part of
the full burn risk assessment. This reevaluation includes the experience gained in the trial burn
along with information from other similar facilities. The approach and results will be included in
the risk assessment report.

ATSDR Response: ATSDR was not provided with the draft proposal on how the TRV emissions
would be projected. This comment was reworded to clarify that we are recommending that the
following assumptions be reevaluated and references provided: (1) that after an initial puff of one
minute duration, the emissions will decrease exponentially to zero within 25 minutes and, (2) that
during the first minute the DRE will decrease from 99.99% to 99%.

Background
Caldwell Systems, Inc. (CSI) operated a hazardous waste incinerator from 1977 to 1988, in
Caldwell County, NC. The hazardous substances burned included: varnish, paint, glue, lacquer,
toluene, xylene, and other solvents used by the regional furniture and pipeline industries, as well
as waste torpedo fuel from the U.S. Navy. This incinerator operated without air pollution control
equipment until 1987. Emissions from the site included smoke from the incinerator and fugitive
emissions from the handling of hazardous wastes.

Original Study

Study of Symptom and Disease PrevalenceCaldwell Systems, Inc. Hazardous Waste IncineratorCaldwell County, North Carolina, September 1993

During July 1991, ATSDR conducted a cross-sectional symptom and disease prevalence study,
collecting questionnaire data from 713 residents living within 1.5 miles of the incinerator (target
area) and 588 residents of a comparison area. Subsequent analysis of this data revealed that
residents of the target area were more likely than residents of the comparison area (after adjusting
for potential confounders) to report recurrent wheezing or coughing, neurologic symptoms
(dizziness and poor coordination), neurologic diseases, and irritative symptoms.

Follow-up Study

Health Outcome Follow-up Study of Residents Living Near the Caldwell Systems, Inc. Site Caldwell County, North Carolina(a draft final report)

In a follow-up study conducted during August 1993, ATSDR administered questionnaires,
pulmonary function tests (PFT), neurobehavioral tests, and tests of the immune system to
participants selected from the original study (above). The follow-up study included 164 target
area participants and 96 comparison area residents. One finding was that pulmonary function test
results were worse among target area participants who reported respiratory symptoms at follow-up than among those who did not. A draft final report is available for review and is expected to
be published early in FY98.

VERTAC/HERCULES SITE, AK

Background

In 1988, the Arkansas Department of Pollution Control and Ecology (ADPC&E) contracted for
the incineration of the drummed waste, using a $10.7 million combined trust fund and letter of
credit obtained from Vertac during bankruptcy litigation. A contract for incineration of the
drummed waste was signed in 1989 between ADPC&E and Vertac Site Contractors (VSC). VSC
is a joint venture of MRK Incineration and Morrison-Knudsen Environmental Services.

In January 1992, the ADPC&E approved the VSC trial burn, and production scale incineration
began. Because the drums were difficult to handle, incineration took longer than expected. There
were extensive legal delays due to lawsuits. In May 1993, the trust fund money had been spent
with about one half of the waste destroyed.

In 1990, the Arkansas Department of Health and the Agency for Toxic Substances and Disease
Registry began planning the first of a series of studies addressing problems due to the presence of
the site. The Historical Exposure Assessment Study and the Inhalation Exposure Assessment
Study were initiated in 1991. The Health Outcome and the Reproductive Health Monitoring
studies were initiated in 1993.

Reproductive Health Monitoring Study
Purposes: 1) To determine if there is a temporal association of birth prevalence rates to the
Jacksonville Superfund sites, and 2) To determine if the birth prevalence rates differ between
Jacksonville and the remainder of Pulaski County.

Results: Examination of adverse reproductive outcomes in Pulaski County over
the period of 1980-1990, was performed to assess possible relationships to the
past chemical manufacturing activities at the Vertac Superfund site in Jacksonville,
Arkansas. Analyses included statistical comparisons of occurrences of fetal
loss, birth defects, developmental disabilities and low birth weight between
Jacksonville and the remainder of the county. Other studies included time trends
and spatial analyses. The findings were:

-

The increased fetal loss rates observed in the Jacksonville
area in the early 1980s was not associated with spatial proximity to the
Vertac Site.

-

No indication of an excess in birth defects related to the
Vertac site was observed.

-

Weak associations were found for a few developmental problems,
(such as seizures and neonatal seizures) and the Vertac site.

-

Several clusters of low birth weight were noted in Pulaski
County, including one to the southeast of the Vertac site.

-

No indication of an association of fetal loss, birth defects
or developmental disabilities with the passage of time was demonstrated.

The localized excess in low birth weight may account for the weak clusters
of developmental disabilities. There is no direct evidence relating the low
birth weight cluster to the southeast of the Vertac site to site activities.
Further spatial studies of low birth weight and developmental disabilities are
recommended, including evaluating possible relationships to body burdens and
environmental data.

On going studies -

Historical Exposure Assessment
Purposes: 1) To determine if exposure to persistent chemicals at the site, including Dioxin and
Dioxin-like compounds for more than 15 years, results in higher body burdens by conducting
biomonitoring activities which include collection of medical history and blood samples; 2) To
determine if exposure to non-persistent chemicals at the site including 2,4-D, 2,4-dichlorophenol,
2,4,5-T and 2,4,5-trichlorophenol for more than one year (as of 1991) results in higher body
burdens by conducting biomonitoring activities which include collection of medical history and
blood samples.

Incinerator Exposure Assessment
Purpose: To determine if remediation activities associated with the site clean-up, particularly
handling and incineration of drummed wastes, results in increases in body burdens of site related
chemicals by conducting pre- and post-incineration biomonitoring activities for estimating blood
lipid concentrations and urine concentrations of site contaminants in nearby residents.

Health Outcome Study
Purpose: To test the hypothesis that "Group living for extended periods in a defined area near or
adjacent to the site have a higher prevalence of acute or chronic illness, plausibly associated with
exposure to persistent pollutants related to the site such as TCDD, than similar groups who live in
an area far away from the site."

Effects of Dioxin-like Compounds on Glucose Regulation and Insulin Sensitivity (Diabetes Report)
Purposes: 1) To determine if there is a positive association between excess blood lipid levels of
TCDD (and TEQ-TCDD) and an increased likelihood that elevated levels of insulin are necessary
to control blood glucose concentrations within desirable physiological limits; and 2) To test if the
association between excessive exposure to TCDD (TEQ-TCDD) and increased insulin concentrations follows a dose response.

Do Waste Incinerators Induce Adverse Respiratory Effects? An Air Quality and
Epidemiological Study of Six Communities in North Carolina.

The University of North Carolina conducted a three-year epidemiological study of the prevalence
and incidence of respiratory effects among residents of communities surrounding three types of
waste incinerators (a biomedical incinerator, a municipal waste incinerator, and a liquid hazardous
waste-burning industrial furnace), and three matched comparison communities.

Purposes: 1) To compare the prevalence of chronic respiratory symptoms, respiratory
hypersensitivity, diminished lung function, upper respiratory tract inflammatory reactions, and
upper and lower respiratory tract diseases in exposed and non-exposed communities, adjusting for
the distribution of known risk factors for these conditions; 2) To select subcohorts of normal and
of hypersensitive adults in these exposed and control communities and to obtain daily
measurements of lung function and respiratory symptoms in these persons over a one month
period, annually, for three years, with simultaneous daily measurements of air quality in each
community; 3) To identify whether subgroups of the population are at higher risk of lung and
respiratory disease from exposure to fugitive or stack emissions from incinerators.

Results from first year: differences in concentrations of particulate matter were detected among
any of the three pairs of study communities. Average fine particulate (PM2.5) concentrations
measured for 35 days varied across study communities from 16 to 32 ug/m3. Within the same
community, daily concentrations of the fine particulate varied by as much as eightfold, from 10 to
80 ug/m3, and were nearly identical within each pair of communities. Direct measurements of air
quality and estimates based on a chemical mass balance receptor model showed that incinerator
emissions did not have a major or even a modest impact on routinely monitored air pollutants. A
onetime baseline descriptive survey (n=6963) did not reveal consistent community differences in
the prevalence of chronic or acute respiratory symptoms between incinerator and comparison
communities, nor were differences seen in baseline lung function tests or in the average peak
expiratory flow rate measured over a period of 35 days. Based on this analysis of the first year of
our study, the investigators concluded that we have no evidence to reject the null hypothesis of no
acute or chronic respiratory effects associated with residence in any of the three incinerator communities.

Results from subsequent years and the final report of this project are yet to be finalized.

1. Olie, K., Addink, R., and Schoonenboom, M. "Metals as Catalysts during the Formation
and Decomposition of Chlorinated Dioxin and Furans in Incineration Processes". Journal of the
Air & Waste Management Association 46:101-105 (February 1998).